No tranny oil during tuning...failure points?


customfab

Member
Aug 7, 2005
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01 RM250. So I will start but saying that I'm an absolute dumbass. I had been adding aftermarket parts & drained my tranny oil without refilling immediately. I meant to get around to it but had no plans to ride or start I was waiting for a new magneto. So after a few weeks I replace the magneto and adding a JD jet kit. So I started the tuning procedures last night but without tranny oil!! :bang:
I realized it after I jumped on the bike and road maybe a 1/4 mile. It seemed to shift fine and I quickly added the required oil and began final tuning. Shortly after running WOT (for the 2nd time but with oil) the motor starting dying & I noticed it was behaving funny. That's it now. She'll fire up very briefly (like 1-2 secs) & then die.
Compression seems ok at 180 psi. I pulled the top end and can't find anything noticeable wrong. Piston diameter within specs, bore ok, etc. All clean, no scoring, no metal particulates, etc.
However, I noticed that the rod doesn't spin freely on the crank. Thoughts on this one? I figure I'm up for some $$ and at least one long day on lower unit rebuild? :bang:
 

customfab

Member
Aug 7, 2005
20
0
_JOE_ said:
The lower end should spin freely. That needs to be sorted out first and foremost.

In process of pulling bottom end and splitting. I have found that the lower rod bearing is toast. Not completely seized up but certainly doesn't spin freely without some major help. I'm hoping that's "it". Not a cheap and easy fix in itself.

I also pulled the oil and submerged a magnet all along the bottom. Good news. Virtually no metal shavings at all. So it would appear the I didn't burn up the tranny as it was only in gear for 1/4 mile.
 

2strokerfun

Member
May 19, 2006
1,500
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You just avoided the perfect storm. Tranny is probably fine is you only rode short distance, but you get to check it out anyway since you'll be splitting the cases. You're lucky you caught this when you did. Could have been a whole lot worse.
 

RM_guy

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Damn Yankees
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Nov 21, 2000
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The odd thing is, lack of tranny oil would not affect the lower rod bearing since that is lubed from the pre-mix.

BTW, how do you like the JD Jetting kit? I put it on my '01 and love it.
 

miggo

Member
Nov 20, 2007
3
0
In a 2 stroke you can have a leak between the crankcase and the top end. If this is the case you will not create enough vacuum to suck in the air/fuel and it wont run. If the bottom end got hot enough to blow out the gasket between the case halves that would cause the problem you are having.

Just a thought.
 

2strokerfun

Member
May 19, 2006
1,500
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Matt90GT said:
maybe you forgot to put in premix also?!!!
That will probably be me soon. I bought a gallon of gas Sunday because it was beautiful and was hoping to ride after I finished painting a room. Well, cold front moved in before I finished painting and I have a gallon of gas without oil in it yet sitting in my garage in the motorcycle (premix) can. Everytime I walk by it, I forget to put a sign on it saying "no oil." I run castor-based oil, so I generally don't mix it ahead of time when gas is going to be sitting in 17-degree garage. I'm a dumbass and I know I'm a dumbass, but I can predict what is going to happen if I don't remember to put a freakin sign on the darned gas can.
 

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